SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd54f15d04cc21915f8eab7c7fdf0ae31853c62dbaf50678e73e815d7fd8a3130' 
  AND token = 'SyFcQr/AyrY5jkr/ANekpGVnz4aVb8NHD2GP/hP/vto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}